São Tomé and Príncipe IBAN Format (ST) — Structure, Length & Example

The São Tomé and Príncipe IBAN is 25 characters long and follows the ISO 13616 standard under the supervision of the Banco Central de São Tomé e Príncipe. This small island nation in the Gulf of Guinea operates a modest but formally structured banking system, and IBANs are used for domestic interbank transfers and international wire payments. São Tomé and Príncipe is not a SEPA country, and cross-border payments travel via the SWIFT network.

São Tomé and Príncipe IBAN at a Glance

• Country code: ST
• Total length: 25 characters (always)
• Format: STkk bbbb ssss aaaaaaaaaaaaa
• BBAN length: 21 characters
• Character types: 4-digit bank code + 4-digit branch code + 13-digit account number (all numeric)

São Tomé and Príncipe IBAN Structure Explained

1. Country Code — ST (2 characters)

The ISO 3166-1 alpha-2 code for São Tomé and Príncipe. Every IBAN from this country begins with ST.

2. Check Digits — kk (2 digits)

Two decimal digits calculated using the MOD-97 algorithm (ISO 7064). These digits allow any system to verify the structural integrity of the IBAN before transmitting it.

3. Bank Code — bbbb (4 digits)

A 4-digit numeric code identifying the institution. The BBAN for São Tomé and Príncipe uses all-numeric characters — there are no alphabetic components in the bank or branch fields. Common bank codes include:

• 0001 — Banco Internacional de São Tomé e Príncipe (BISTP)
• 0002 — Energy Bank São Tomé e Príncipe
• 0003 — Afriland First Bank STP

4. Branch Code — ssss (4 digits)

A 4-digit numeric branch identifier. Given the small size of the banking network, many banks operate a single or small number of branches on the two main islands.

5. Account Number — aaaaaaaaaaaaa (13 digits)

A 13-digit numeric account number assigned by the bank to the account holder. All digits, no alpha characters in this field.

São Tomé and Príncipe IBAN Example

ST68 0002 0001 1019 2194 20105

(Example only — not a real account)

• Country: ST
• Check digits: 68
• Bank code: 0002
• Branch code: 0001
• Account number: 1019219420105

How IBAN Validation Works for ST

1. Country code check: First two characters must be exactly ST.
2. Length check: Total character count (spaces removed) must be exactly 25.
3. Character type check: Positions 3–25 must all be decimal digits (no alpha characters anywhere in the BBAN for this format).
4. MOD-97 check: Move the first four characters to the end, replace S (= 28) and T (= 29) with their numeric equivalents, then compute the remainder divided by 97. A valid IBAN produces a remainder of 1.

Verify any São Tomé and Príncipe IBAN using the ibanchecker.cash validator, which checks all four validation steps and reports the bank code.

Banking Context: São Tomé and Príncipe

São Tomé and Príncipe is a small island nation with a population of approximately 230,000. The banking sector is supervised by the Banco Central de São Tomé e Príncipe and consists of a handful of commercial banks, the largest of which is BISTP (Banco Internacional de São Tomé e Príncipe). The country's currency is the São Tomé and Príncipe Dobra (STN), which is pegged to the euro at a fixed rate through an agreement with Portugal and the European Union.

• Currency: STN (São Tomé and Príncipe Dobra), pegged to EUR at 1 EUR = 24.5 STN
• São Tomé and Príncipe is not a SEPA country
• International transfers require the IBAN plus the bank's SWIFT BIC code
• Due to the euro peg, many international transfers arrive in euros and are converted domestically

Limited International IBAN Recognition

While the ST IBAN format is registered under ISO 13616, São Tomé and Príncipe's small banking sector means that international recognition is uneven. Some European and North American payment platforms and bank portals may not include ST in their country dropdown or may not accept 25-character IBANs with an ST prefix. In such cases, provide the SWIFT BIC and account number in addition to the IBAN, and contact your bank to confirm the payment can be routed correctly.

Common São Tomé and Príncipe IBAN Mistakes

Wrong Length — 23 or 27 Characters

The ST IBAN is exactly 25 characters. Length errors are almost always caused by dropping or duplicating one of the digit fields. Remove all spaces before counting.

Alpha Characters in the BBAN

Unlike most African and Gulf IBANs (which use letters for bank codes), the entire ST BBAN is numeric. An IBAN with letters after the check digits is invalid for this country.

Confusing Bank and Branch Codes

Both the bank code and branch code are 4 numeric digits each, making transpositions between them common. Confirm both fields with your beneficiary or bank statement.

Last updated: June 2026